It has been common practice that refrigerant compositions, such as are used for refrigerators, air conditioners climate control units, industrial chilling units, and food transport and storage units, are primarily composed of substantially only one compound or component. For example, methane series CFCs, such dichlorodifluormethane (CFC-12) and methane series HCFCs such as chlorodifluormethane (HCFC-22) have commonly been used as single component refrigerants.
More recently there have been substantial reasons relating to environmental concerns to discontinue use of CFCs. For example, it is now known that CFC's tend to react with the ozone layer around the earth and thereby result in some level of ozone depletion. As a result various governmental and international organizations have been engaged in efforts to reduce or eliminate the use of CFCs. In response to these pressures, and perhaps for other reasons as well, refrigerant compositions are more frequently composed of two or more components. Generally, the refrigerant composition comprises a blend or mixture of two or more compounds, preferably but not necessarily excluding (CFCs) or (HCFCs), selected to have the desired vapor pressure, boiling point, etc. deemed to be desirable for the intended applications. In fact, the present inventors are not aware at the present time of a alternative compound which can be substituted directly in devces which use HCFC-22 as a single component refrigerant, and therefore at the present time the most promising candidates are mixed refrigerants obtained by mixing different types of compounds, including HFCs, hydrofluoroethers (hereunder referred to as “HFEs”), fluoroethers (hereunder referred to as “FEs”) and fluoroiodocarbons (hereunder referred to as “FICs”).
Generally, it is not possible and/or not desirable to attempt to use any one single mixed refrigerant composition for all refrigerant uses, and therefore various types of mixed refrigerants are being employed which contain combinations of 2 or 3 components in different proportions for adjustment of the properties and performance to allow their application for different uses and devices.
Methods and systems for the production of multi-component refrigerant compositions are known. For example, Australian patent application AU199852033 B2 describes a process for producing mixed refrigerants. The process described in this patent application, however, is relatively complex to execute, and furthermore is relatively time-consuming to implement. More specifically, this patent discloses a process for producing multi-component refrigerant compositions that requires a careful selection of the density of the individual components which are to be incorporated into the composition, as well as a specific sequence for the addition of the components. For three component refrigerant compositions, for example, it is therefore required to first introduce a first component into a vessel in which the mixing will be conducted and ensuring that this component has the proper density relative to the densities of the other components. It is only after this component is in the vessel that the process permits a second component to be introduced into the vessel, but once again assuring that the component with the proper liquid density is introduced into the process. Finally, once each of the first and second components are fully charged into the vessel, the third component can then be introduced into the vessel.
Applicants have therefore recognized a need for methods of producing multi-component refrigerant compositions relatively quickly, accurately, and cost effectively.